Cancer is a complex, multifactorial disease induced by exogenous damaging agents and endogenous metabolic processes (1, 2). Of particular interest in the study of carcinogenesis are oxidative processes (2, 3). Ingested externally generated oxidative products are known to be carcinogenic. In general, it is estimated that diets and foods contribute to about one third of all incidences of cancer and cardiovascular disease.
Deep frying is a frequent method of food preparation, especially in fast food businesses, due to popularity of fried foods. Oxidation of frying oil at high temperatures generates numerous oxidative products, some of which have undesirable effects on food quality and safety (4, 5). Oxidation of fats and oils in deep frying is mediated by free radical processes (5) which potentlate (amplify) decomposition through chain propagation (6). Oxidative chain propagation, however, is preventable by antioxidants (6).
Hence, application of antioxidants could be used to control the extent of oxidation, i.e., oxidative decomposition of frying oils, extending the usable lifetime and reducing the potential toxicity of oils. Antioxidants, in general, are known to have anticarcinogenic properties (7, 8), as well as preventers of cardiovascular diseases (8), due to suppression of oxidative processes (8).
Propagation cation of a chain reaction occurs by the reaction of peroxy radicals with a lipid molecule EQU HLOO+H.sub.2 L.fwdarw.HLOOH+HL
This chain reaction can be inhibited by electron donation either by an electrode or antioxidant EQU HLOO+e.sup.- .fwdarw.HLOO.sup.- EQU HLOO.sup.- +H.fwdarw.HLOOH.
Chain reactions in oxidation of fats and oils during frying and deep frying of foods are propagated by oxy radicals. Chain reactions can be inhibited by neutralization of oxy radicals. Oxy radicals can be neutralized by electrochemical or chemical electron donation. Consequently, the rate and extent of oxidation can be controlled to a great degree in order to optimize the flavor, extend the lifetime of oils, and reduce formation of potentially toxic products.
References:
1. Loeb, L. A., Mutator phenotype may be required for multistage carcogenesis, Cancer Res. 51, (1991), 3075.
2. Cerrutti, P. A. and Trump, B. F., Inflammation and oxidative stress in carcinogenesis, Cancer Cells, 3, (1991), 1.
3. Simic, M. G., Urinary biomarkers and the rate of DNA damage in carcinogenesis and anticarcinogenesis, Mut. Res. 267, (1992), 277.
4. St. Angelo, A. J. (Ed), Lipid Oxidation in Food, American Chemical Society Symposium Series 500 (1992).
5. Perkins, E. G., Effect of lipid oxidation in oil and food quality in deep frying, American Chemical Society Symposium Series 500, (1992), 310.
6. Simic, M. G., Javanovic, S. V., and Niki, E., Mechanism of lipid oxidative processes and their inhibition, American Chemical Society Symposium Series 500, (1992), 14.
7. De Flora, S., Special Issue Mutt. Res. 267, (1992).
8. Slater, T. F., and Block, G. (Ed), Antioxidant Vitamins and b-Carotene in Disease Prevention, Am. J. Clinical Nutrition, 53, (1992), 1.